You see them in the grocery store and on the street, wearing their jackets or harnesses. Guide dogs lead the blind and visually impaired. Hearing dogs alert their owners to sounds. Some service dogs assist the physically impaired. Mobility dogs provide stability for people who are unsteady on their feet. Medical-alert dogs can sense when their owners are about to have a seizure or experience a diabetic drop in their blood-sugar levels. Others check their owner’s foods for life-threatening allergens. Some assist owners who have autism or post-traumatic stress disorder.

Al Schwarz suffers from hearing loss. His dog Sam, a standard poodle trained by My Service Dog, alerts him to sounds such as the doorbell, the phone and sirens. Over the four years Schwarz, who is 70, has had Sam, he has also begun walking with a cane. He and Allie Keaton, Sam’s trainer, have taught Sam other skills, such as how to retrieve items and open doors.

“Sam is also my companion,” says Schwarz, who lives in Goldberg B’nai B’rith Towers, a residential community for senior citizens and mobility-impaired adults. “Before I had Sam, I knew maybe eight or ten people here. Now, people may not know my name, but everyone knows Sam’s...more.